Systems and methods for real time tracking of targets in radiation therapy and other medical applications

• US 20060079764A1
• Filed: 06/24/2005
• Published: 04/13/2006
• Est. Priority Date: 07/23/2004
• Status: Abandoned Application

• Current Assignee: Varian Medical Systems Incorporated (Siemens AG)
• Original Assignee: Varian Medical Systems Incorporated (Siemens AG)
• Inventors: Wright, J. Nelson, Dimmer, Steven C.
• Application Number:
  US11/166,801
• Publication Number:
  US 20060079764A1
• Time in Patent Office: Days
• US Class Current: 600/431
• CPC Class Codes: A61B 2034/2051 Electromagnetic tracking systems
• CPC Class Codes: A61B 2034/252 indicating steps of a surgical procedure
• CPC Class Codes: A61B 2090/3908 Soft tissue, e.g. breast tissue
• CPC Class Codes: A61B 2090/3954 magnetic, e.g. NMR or MRI
• CPC Class Codes: A61B 2090/3958 emitting a signal
• CPC Class Codes: A61B 2090/3995 Multi-modality markers
• CPC Class Codes: A61B 34/20 Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis
• CPC Class Codes: A61B 34/25 User interfaces for surgical systems
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: A61B 5/06 Devices, other than using radiation, for detecting or locating foreign bodies for removing same A61B17/50 ; determining position of probes within or on the body of the patient
• CPC Class Codes: A61B 6/12 Arrangements for detecting or locating foreign bodies
• CPC Class Codes: A61B 8/0833 involving detecting or locating foreign bodies or organic structures
• CPC Class Codes: A61B 90/36 Image-producing devices or illumination devices not otherwise provided for
• CPC Class Codes: A61B 90/39 Markers, e.g. radio-opaque or breast lesions markers
• CPC Class Codes: A61N 2005/1051 using an active marker markers in general A61B90/39
• CPC Class Codes: A61N 5/1049 for verifying the position of the patient with respect to the radiation beam
• CPC Class Codes: A61N 5/1067 in real time, i.e. during treatment
• CPC Class Codes: A61N 5/107 in real time, i.e. during treatment

Abstract

Systems and methods for tracking targets in real time for radiation therapy and other applications. In one embodiment, a method includes collecting position information of a marker implanted within a patient at a site relative to the target at a time t_n, and providing an objective output indicative of the location of the target based on the position information collected at time t_n. The objective output is provided to a memory device, user interface, and/or radiation delivery machine within 1 ms to 2 seconds of the time t_n when the position information was collected. This embodiment of the method can further include providing the objective output at a periodicity of 10-200 ms during at least a portion of a treatment procedure. For example, the method can further include generating a beam of ionizing radiation and directing the beam to a machine isocenter, and continuously repeating the collecting procedure and the providing procedure every 10-200 ms while irradiating the patient with the ionizing radiation beam.

Claims

1. In medical applications, a method for tracking a target in a human patient using a marker secured in the patient such that the marker is substantially fixed relative to the target, the method comprising:

collecting position data of the marker;

determining the location of the marker in an external reference frame based on the position data; and

providing an objective output in the external reference frame that is (a) responsive to the location of the marker and (b) provided at a frequency such that the tracking error is less than 5 mm.

2. The method of claim 1 wherein the marker comprises a small transponder that wirelessly transmits a location signal in response to a wirelessly transmitted non-ionizing excitation energy, and wherein collecting the position data comprises sensing the location signal.

3. The method of claim 2 wherein the marker is configured to be implanted in the patient, and wherein the method further comprises implanting the marker at a site at least proximate to the target such that the marker moves in direct correlation to movement of the target.

4. The method of claim 1 wherein the marker comprises a small leadless marker configured to be implanted in the patient and having a transponder that wirelessly transmits a location signal in response to a wirelessly transmitted non-ionizing excitation energy, and wherein the method comprises implanting the marker and collecting the position data comprises sensing the location signal.

5. The method of claim 1 wherein the marker comprises a small alternating magnetic transponder that wirelessly transmits an alternating magnetic location signal in response to a wirelessly transmitted alternating magnetic field, and wherein collecting the position data comprises sensing the alternating magnetic location signal.

6. The method of claim 1 wherein the objective output is provided without human interpretation of at least one of the position data and the determined location of the marker.

7. The method of claim 1 wherein the objective output comprises a three-dimensional coordinate in the external reference frame.

8. The method of claim 1 wherein the objective output comprises an offset value between the target and a desired location for the target that is determined in a computer system.

9. The method of claim 1 wherein the position data is collected at a time t_n, and wherein providing the objective output responsive to the location of the target comprises providing the objective output to at least one of a user interface, a memory device, a computer and a medical device within a latency period of not greater than approximately 5 seconds of time t_n and at a periodicity not greater than approximately 15 seconds.

10. The method of claim 9 wherein the latency period is not greater than approximately 2 seconds of time t_n and at a periodicity not greater than approximately 2 seconds.

11. The method of claim 9 wherein the latency period is not greater than approximately 1 second of time t_n and at a periodicity not greater than approximately 1 second.

12. The method of claim 9 wherein the latency period is not greater than approximately 100 ms of time t_n and at a periodicity not greater than approximately 200 ms.

13. The method of claim 9 wherein the latency period is not greater than approximately 50 ms of time t_n and at a periodicity not greater than approximately 50 ms.

14. The method of claim 9 wherein the periodicity is approximately 12.5 ms.

15. The method of claim 9 wherein the periodicity is approximately 16.67 ms.

16. The method of claim 9 wherein the periodicity is approximately 20 ms.

17. The method of claim 1, further comprising positioning the patient to locate the target at a desired location relative to an isocenter of a radiation delivery device while performing the collecting, determining and providing procedures.

18. The method of claim 1, further comprising irradiating the patient with a high-intensity ionizing beam directed to an isocenter of a radiation delivery device while performing the collecting, determining and providing procedures.

19. The method of claim 18, further comprising controlling at least one of a patient position and a parameter of the high-intensity ionizing beam while performing the collecting, determining and providing procedures.

20. The method of claim 19, further comprising controlling an on-off state of the non-ionizing beam such that the non-ionizing beam is on when the target is indicated as being located at a desired position relative to the machine isocenter.

21. The method of claim 19, further comprising moving the patient to position the target at a desired location relative to the machine isocenter.

22. The method of claim 19, further comprising changing a shape of the non-ionizing beam.

23. The method of claim 1 wherein providing the objective output in the external reference frame comprises providing the objective output at least substantially contemporaneously with collecting the position data used to determine the location of the marker.

24. The method of claim 1 wherein the frequency comprises providing a plurality of objective outputs during a beam-on period.

25. In radiation therapy for treating a target within a patient, a method for tracking the target in real time using a marker implanted in the patient at a site relative to the target, the method comprising:

collecting position data of the marker at a time t_n;

determining the location of the marker in an external reference frame based on the position data;

providing an objective output indicative of the location of the target to a user interface, a memory device and/or a radiation delivery device within a latency not greater than 2 seconds of time t_n;

repeating the providing procedure at least every 2 seconds.

26. The method of claim 25 wherein the marker comprises a small transponder that wirelessly transmits a location signal in response to a wirelessly transmitted non-ionizing excitation energy, and wherein collecting the position data comprises sensing the location signal wirelessly transmitted by the marker.

27. The method of claim 25 wherein the marker comprises a small alternating magnetic transponder that wirelessly transmits an alternating magnetic location signal in response to a wirelessly transmitted alternating magnetic field, and wherein collecting the position data comprises sensing the alternating magnetic location signal wirelessly transmitted by the marker.

28. The method of claim 25 wherein the objective output comprises an offset coordinate between the location of the target and an isocenter of the radiation delivery device.

29. The method of claim 28 wherein providing the objective output comprises sending the offset coordinate to the user interface, the memory device and/or the radiation delivery device within a latency of approximately 1 ms to approximately 1 second of time t_n and at a periodicity of approximately 1 ms to approximately 1 second.

30. The method of claim 28 wherein providing the objective output comprises sending the offset coordinate to the user interface, the memory device and/or the radiation delivery device within a latency of approximately 1 ms to approximately 100 ms of time t_n and at a periodicity of approximately 1 ms to approximately 200 ms.

31. The method of claim 28 wherein providing the objective output comprises sending the offset coordinate to the user interface, the memory device and/or the radiation delivery device within a latency of approximately 10 ms to approximately 50 ms of time t_n and at a periodicity of approximately 20 ms to approximately 50 ms.

32. The method of claim 25 wherein the objective output comprises a coordinate in the external reference frame related to the location of the target, and wherein providing the objective output comprises sending the coordinate to the user interface within a latency of approximately 10 ms to approximately 100 ms of time t_n and at a periodicity of approximately 10 ms to approximately 50 ms.

33. The method of claim 32 wherein the periodicity is approximately 12.5 ms.

34. The method of claim 32 wherein the periodicity is approximately 16.67 ms.

35. The method of claim 32 wherein the periodicity is approximately 20 ms.

36. The method of claim 25, further comprising positioning the patient to locate the target at a desired location relative to an isocenter of the radiation delivery device while performing the collecting, determining and providing procedures.

37. The method of claim 36 wherein the objective output comprises an offset coordinate between the location of the target and a desired site for the target relative to the isocenter of the radiation delivery device, and wherein providing the objective output comprises sending the offset coordinate to the user interface, the memory device and/or the radiation delivery device within a latency of approximately 1 ms to approximately 100 ms of time t_n and at a periodicity of approximately 1 ms to approximately 200 ms.

38. The method of claim 37 wherein providing the objective output comprises sending the offset coordinate to the user interface within a latency of approximately 10 ms to approximately 100 ms of time t_n and at a periodicity of approximately 10 ms to approximately 50 ms.

39. The method of claim 37 wherein providing the objective output comprises sending the offset coordinate to the radiation delivery device within a latency of approximately 1 ms to approximately 100 ms of time t_n and at a periodicity of approximately 1 ms to approximately 50 ms, and wherein the radiation delivery device automatically moves a patient support table according to the offset coordinate.

40. The method of claim 25, further comprising irradiating the target with a radiation beam from the radiation delivery device while performing the collecting, determining and providing procedures.

41. The method of claim 40 wherein the objective output comprises an offset coordinate between the location of the target and a desired site for the target relative to an isocenter of the radiation delivery device, and wherein providing the objective output comprises sending the offset coordinate to the radiation delivery device within a latency of approximately 1 ms to approximately 100 ms of time t_n and at a periodicity of approximately 1 ms to approximately 200 ms.

42. The method of claim 41, further comprises controlling a parameter of the radiation delivery device according to the offset coordinate.

43. The method of claim 42 wherein controlling the parameter of the radiation delivery device comprises terminating the radiation beam when the offset coordinate exceeds a predetermined value indicating that the target is outside of an acceptable range of the isocenter.

44. The method of claim 42 wherein controlling the parameter of the radiation delivery device comprises automatically moving a patient support table according to the offset coordinate.

45. In radiation therapy for treating a target in a patient, a method of tracking the target, comprising:

obtaining position data of a marker situated within the patient at a site relative to the target;

determining a location of the marker in an external reference frame based on the position data; and

providing to a user interface an objective output indicative of the location of the target based on the determined location of the marker at (a) a sufficiently high frequency so that pauses in representations of the target location at the user interface are not readily discernable by a human and (b) a sufficiently low latency to be at least substantially contemporaneous with obtaining the position data of the marker.

46. The method of claim 45 wherein the marker comprises a small transponder that wirelessly transmits a location signal in response to a wirelessly transmitted non-ionizing excitation energy, and wherein obtaining the position data comprises sensing the location signal wirelessly transmitted from the marker.

47. The method of claim 45 wherein the marker comprises a small alternating magnetic transponder that wirelessly transmits an alternating magnetic location signal in response to a wirelessly transmitted alternating magnetic field, and wherein obtaining the position data comprises sensing the alternating magnetic location signal wirelessly transmitted by the marker.

48. The method of claim 45 wherein the position data is obtained at a time t_n and the objective output comprises an offset coordinate between the location of the target and a desired site for the target relative to an isocenter of a radiation delivery device.

49. The method of claim 48 wherein providing the objective output comprises sending the offset coordinate to the user interface and/or the radiation delivery device within a latency of approximately 1 ms to approximately 1 second of time t_n and at a periodicity of approximately 1 ms to approximately 1 second.

50. The method of claim 48 wherein providing the objective output comprises sending the offset coordinate to the user interface and/or the radiation delivery device within a latency of approximately 1 ms to approximately 100 ms of time t_n and at a periodicity of approximately 1 ms to approximately 200 ms.

51. The method of claim 48 wherein providing the objective output comprises sending the offset coordinate to the user interface and/or the radiation delivery device within a latency of approximately 10 ms to approximately 50 ms of time t_n and at a periodicity of approximately 20 ms to approximately 50 ms.

52. The method of claim 45 wherein the position data is obtained at a time t_n and the objective output comprises a coordinate in the external reference frame related to the location of the target, and wherein providing the objective output comprises sending the coordinate to the user interface within a latency of approximately 10 ms to approximately 100 ms of time t_n and at a periodicity of approximately 10 ms to approximately 50 ms.

53. The method of claim 45, further comprising positioning the patient to locate the target at a desired location relative to an isocenter of a radiation delivery device while performing the obtaining, determining and providing procedures.

54. The method of claim 45 wherein the position data is obtained at a time t_n and the objective output comprises an offset coordinate between the location of the target and a desired site for the target relative to the isocenter of the radiation delivery device, and wherein providing the objective output comprises sending the offset coordinate to the user interface and/or the radiation delivery device within a latency of approximately 1 ms to approximately 100 ms of time t_n and at a periodicity of approximately 1 ms to approximately 200 ms.

55. The method of claim 54 wherein providing the objective output comprises sending the offset coordinate to the user interface within a latency of approximately 10 ms to approximately 100 ms of time t_n and at a periodicity of approximately 10 ms to approximately 50 ms.

56. The method of claim 54 wherein providing the objective output comprises sending the offset coordinate to the radiation delivery device within a latency of approximately 1 ms to approximately 100 ms of time t_n and at a periodicity of approximately 1 ms to approximately 50 ms, and wherein the radiation delivery device moves a patient support table according to the offset coordinate.

57. The method of claim 45, further comprising irradiating the target with a radiation beam from a radiation delivery device while performing the obtaining, determining and providing procedures.

58. The method of claim 57 wherein the position data is obtained at a time t_n and the objective output comprises an offset coordinate between the location of the target and a desired site for the target relative to an isocenter of the radiation delivery device, and wherein providing the objective output comprises sending the offset coordinate to the radiation delivery device within a latency of approximately 1 ms to approximately 100 ms of time t_n and at a periodicity of approximately 1 ms to approximately 200 ms.

59. The method of claim 58, further comprises controlling a parameter of the radiation delivery device according to the offset coordinate.

60. The method of claim 59 wherein controlling a parameter of the radiation delivery device comprises terminating a radiation beam when the offset coordinate exceeds a predetermined value indicating that the target is outside of an acceptable range of the isocenter.

61. The method of claim 59 wherein controlling a parameter of the radiation delivery device comprises automatically moving a patient support table according to the offset coordinate.

62. A radiation therapy system for treating a target of a patient using a marker implanted in the patient at a site relative to the target, the system comprising:

a radiation delivery device including a beam generator for generating a beam of ionizing radiation, an isocenter, and an aiming system for directing the beam to the isocenter;

a detector that obtains position data of the marker at a time t_n; and

a computer operatively coupled to the detector to receive the position data, the computer having a computer operable medium that determines a location of the marker based on the position data and provides an objective output indicative of a location of the target to a user interface, a memory device, and/or a radiation delivery device within a latency of not greater than 2 seconds from time t_n and at a periodicity of not greater than 2 seconds.

63. The radiation therapy system of claim 62, further comprising an excitation source configured to wirelessly transmit a non-ionizing excitation energy, a marker having a small transponder configured to wirelessly transmit a location signal in response to the wirelessly transmitted non-ionizing excitation energy, and wherein the detector is configured to sense the location signal wirelessly transmitted by the marker.

64. The radiation therapy system of claim 62, further comprising an excitation source configured to wirelessly transmit an alternating magnetic field, a marker having a small alternating magnetic transponder that wirelessly transmits an alternating magnetic location signal in response to the wirelessly transmitted alternating magnetic field, and wherein the detector comprises a coil configured to sense the alternating magnetic location signal wirelessly transmitted by the marker.

65. The radiation therapy system of claim 62 wherein the objective output comprises an offset coordinate between the location of the target and a desired site for the target relative to an isocenter of the radiation delivery device.

66. The radiation therapy system of claim 65 wherein the computer-operable medium sends the offset coordinate to the user interface, the memory device and/or the radiation delivery device within a latency of approximately 1 ms to approximately 1 second of time t_n and at a periodicity of approximately 1 ms to approximately 1 second.

67. The radiation therapy system of claim 65 wherein the computer-operable medium sends the offset coordinate to the user interface, the memory device and/or the radiation delivery device within a latency of approximately 1 ms to approximately 100 ms of time t_n and at a periodicity of approximately 1 ms to approximately 200 ms.

68. The radiation therapy system of claim 65 wherein the computer-operable medium sends the offset coordinate to the user interface, the memory device and/or the radiation delivery device within a latency of approximately 10 ms to approximately 50 ms of time t_n and at a periodicity of approximately 20 ms to approximately 50 ms.

69. The radiation therapy system of claim 65 wherein the objective output comprises a coordinate in the external reference frame related to the location of the target, and wherein the computer-operable medium sends the coordinate to the user interface within a latency of approximately 10 ms to approximately 100 ms of time t_n and at a periodicity of approximately 10 ms to approximately 50 ms.

70. The radiation therapy system of claim 62, wherein the computer-operable medium sends a signal for positioning the patient to locate the target at a desired location relative to an isocenter of the radiation delivery device.

71. The radiation therapy system of claim 70 wherein the objective output comprises an offset coordinate between the location of the target and an isocenter of the radiation delivery device, and the computer-operable medium sends the offset coordinate to the user interface, the memory device and/or the radiation delivery device within a latency of approximately 1 ms to approximately 100 ms of time t_n and at a periodicity of approximately 1 ms to approximately 200 ms.

72. The radiation therapy system of claim 71 wherein the computer-operable medium sends the offset coordinate to the user interface within a latency of approximately 10 ms to approximately 100 ms of time t_n and at a periodicity of approximately 10 ms to approximately 50 ms.

73. The radiation therapy system of claim 71 wherein the computer-operable medium sends the offset coordinate to the radiation delivery device within a latency of approximately 1 ms to approximately 100 ms of time t_n and at a periodicity of approximately 1 ms to approximately 50 ms, and wherein the radiation delivery device is configured to automatically move a patient support table according to the offset coordinate.

74. The radiation therapy system of claim 62 wherein the objective output comprises an offset coordinate between the location of the target and an isocenter of the radiation delivery device, and wherein the computer-operable medium sends the offset coordinate to the radiation delivery device within a latency of approximately 1 ms to approximately 100 ms of time t_n and at a periodicity of approximately 1 ms to approximately 200 ms.

75. A tracking system for treating a target of a patient using a marker implanted in the patient at a site relative to the target, the system comprising:

a detector that obtains position data of the marker at a time t_n; and

a computer operatively coupled to the detector to receive the position data, the computer having a computer operable medium that determines a location of the marker based on the position data and provides an objective output indicative of a location of the target within a latency of 10-200 ms from time t_n and at a periodicity of 10-100 ms.

76. A method of treating a target of a patient with an ionizing radiation, comprising:

generating a beam of ionizing radiation and directing the beam relative to the target;

collecting position information of a marker implanted within a patient at a site relative to the target while directing the beam toward the beam isocenter;

providing an objective output indicative of a location of the target relative to the beam isocenter based on the collected position information; and

correlating the objective output with a parameter of the beam.

77. A method of treating a target of a patient with an ionizing radiation, comprising:

generating a beam of ionizing radiation and directing the beam relative to the target with a multi-leaf collimator;

collecting position information of a marker implanted within a patient at a site relative to the target while directing the beam toward the beam isocenter; and

providing an objective output indicative of a location of the target of the patient based on the collected position information relative to the beam isocenter and controlling a configuration of the multi-leaf collimator based on the objective output.

78. A method of treating a target of a patient with an ionizing radiation, comprising:

generating a beam of ionizing radiation and directing the beam relative to the target; and

operating a localization system to (a) collect position information of a marker implanted within a patient at a site relative to the target while directing the beam toward the beam isocenter and (b) provide an objective output indicative of a location of the target relative to the beam isocenter based on the collected position information of the marker while directing the beam toward the beam isocenter for a period of at least 10 seconds without recalibrating the localization system.